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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?DOFkQn54UO6q9lc6wvrK7cPpDRdIa/WOWU5eMaCGswoFrNLMrgUdHf4yBzHm?= =?us-ascii?Q?NE+N5ZqEIujIx1weuaeKbjPOXu1IiehMcCB/ltoP8Ud+jhO16StKHDQD4sZn?= =?us-ascii?Q?ayitonK6y0oDq66lVUAaD7dJIV24zsejwxZSsWUdOMxLh3+moMBmOl3B5a1J?= =?us-ascii?Q?W9RUB0Xn4R/ovtv7hIr3KT8+zSs5JZwxiariund6e4/CgvNYJ9JqcGYIjMlF?= =?us-ascii?Q?gn+xX+8qUGE5zzWCQuL/fia9o0KwdSHAzI5U7oXd8R6C/st5r+hqCspkpR8I?= =?us-ascii?Q?8kzlP7TDTrQbYG7mnqIAESm7jhT1gwaK/Nuzi6y385PhyH2n475OF4OiWRqW?= =?us-ascii?Q?2h+iK8Nhe4Gl+B5Jqhk6mhz8pOIjvJujJoaGsNNj7O7Jw6KInrtSU4UCk80T?= =?us-ascii?Q?AN4viRlAc0sV3iEieirgdo9eN77oLqAI3Mc8TzSMO1EMMk9CFGrbVJmTevx9?= =?us-ascii?Q?3BpZyxmksYlOmF7lXRJiBCCdkmb/U26UGL2XoWMFbh0BPY1rYZitNkBQGWGE?= =?us-ascii?Q?gAvnlBERjaC8r9ShyqKHz6PrkMtfR4l0oIO9u0jAZVO2alTUCQfUsyVlQfYm?= =?us-ascii?Q?YpGTBlw/n1cuQ8z/lfYhK0rrazDTIiTD+J2Aw9/wUFBqhIT5s6TvdPWMOBni?= =?us-ascii?Q?O9G20KhRl4I/hqeEUatbyhvPAffsn2CFC9mYfbJdxUKLaeCzZEi3NBOoouY6?= =?us-ascii?Q?rFn70YBxNhLPZV68sVF2zlzRAgd1C7bCGyzzrRTpv9L97HyJisXmOI/JggKx?= =?us-ascii?Q?Mn3olhTLP4YcqhG6DDn6S6vAPFaYDhC3GuAjLg7DbgCsBj+GdWVfeI+AG8Dr?= =?us-ascii?Q?pkbS1rW39fA9sHyPlGhuZsG0XCWPYIIo6TkO7R1SU2e/DFFUqpX29obmFUqI?= =?us-ascii?Q?AC7ZANX4NVGSpUTqPZwRGL6sxxf3KxxTHvAedCnpiGd8uyy2Y2YLjiAs6A1w?= =?us-ascii?Q?nUCp0tK/b9b7vundOjn1l+Ptf2Wr1i86r1Adhn0xW0U4mexCAKrzg/ZrTCgB?= =?us-ascii?Q?hfpG8BOvNhnHRQS+S7hB5bQ+ulbM3gVx4QkXG2T1OlPnBEiEiKdS7/O7dpTy?= =?us-ascii?Q?PCQbAYktRTfM5El0Ns8YWY+q4zbNJeqkavgnrmaPBNOEaMk5I9lV9jRGfU87?= =?us-ascii?Q?ZOniHB0thshRi5HimleGgsJEk+QZTLZas6IK9IfvPUUWHXht8wv0URd9jT+M?= =?us-ascii?Q?rX1/dpBU2jkwCyk8ac0nbfYGcQRHEXImPXWVZSz7AQV3KMkAT2QihESGWNdq?= =?us-ascii?Q?JhF3cnnj+vmyWahfauwJXDt2nNP+BcPCEfLTAQ91SWGhpfEywBDv0Z/Fa6Tk?= =?us-ascii?Q?1xEHNoOVfXEf3bAPheE6j0w7Cnwui2qvCFj9vcZI0EaXWfGHyyBkDHPOHKI+?= =?us-ascii?Q?uf2MeomePOrjgnGoXAyWzX+cT+WTBdYbVxBZSsgBbzXoiGKM0j9dW3f8PsIz?= =?us-ascii?Q?VvXhO42N1S4rRbe9Yz9wdp/Ty7Jb+RyEy/0Q81pqWTv2tlqdSCkEmgP60GeY?= =?us-ascii?Q?j1zSKbBGuhJcLxTgyK9pNvktxMEVYSDwc1cNiaH/m6J+UBn12VNW8lhI9Zyd?= =?us-ascii?Q?dCHk4jiMRZuwoBhqnq8YsTcZe+yMx7sFoh9hpdHj?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 34281283-fdf9-460d-17c2-08dc662485dd X-MS-Exchange-CrossTenant-AuthSource: CYYPR12MB8750.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Apr 2024 19:10:23.2447 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: BYFwQFz/uj4AD5UMt9xiiaVQiE51y0QzcN7LDpIfA5FJGmeQ9bly6BVOd4DWiETOFvCmhQ2Jjpr2eDyEs4r74Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB8814 On 03.04.24 08:47:12, Dave Jiang wrote: > The while() loop in cxl_endpoint_get_perf_coordinates() checks to see if > 'iter' is valid as part of the condition breaking out of the loop. > is_cxl_root() will stop the loop before the next iteration could go NULL. > Remove the iter check. > > The presence of the iter or removing the iter does not impact the behavior > of the code. This is a code clean up and not a bug fix. > > Reviewed-by: Jonathan Cameron > Reviewed-by: Davidlohr Bueso > Reviewed-by: Dan Williams > Signed-off-by: Dave Jiang > --- > drivers/cxl/core/port.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index 2b0cab556072..6cbde50a742b 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -2197,7 +2197,7 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port, > * port each iteration. If the parent is cxl root then there is > * nothing to gather. > */ > - while (iter && !is_cxl_root(to_cxl_port(iter->dev.parent))) { > + while (!is_cxl_root(to_cxl_port(iter->dev.parent))) { I am seeing the following mainline after [1]: [ 39.815379] cxl_acpi ACPI0017:00: not a cxl_port device [ 39.827123] WARNING: CPU: 46 PID: 1754 at drivers/cxl/core/port.c:592 to_cxl_port+0x56/0x70 [cxl_core] ... plus some related subsequent NULL pointer dereference: [ 40.718708] BUG: kernel NULL pointer dereference, address: 00000000000002d8 This changes looks related. I am going to dig deeper here but just a headsup in advance. Note this is tested on an RCH topology. Thanks, -Robert [1] commit 586b5dfb51b9 ("Merge tag 'cxl-fixes-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl"): > cxl_coordinates_combine(&c, &c, &dport->sw_coord); > c.write_latency += dport->link_latency; > c.read_latency += dport->link_latency; > -- > 2.44.0 >